Should air check valve in Autotrol 255 be full of water or air?

Have a newly-installed softener with an Autotrol 255 valve. Before I call the installer back--should the air check valve be full of water or air? Would there be a good reason that there is no check ball in the air check valve? Could this be the reason that the brine tank refills with water (at least half full or more) after the system regenerates? The water stays well above the salt level.

If it's a softener, it should be full of water. There should be an air check ball in it as well. There can also be an air check in the brine tank on most softeners.

I don't know how big this unit is, but a half full brine tank sounds like a lot of water. One gallon of water dissolves around 2.5 lbs of salt, so with a unit that should be using somewhere near 12 lbs of salt per backwash, that's a lot of water in a 30 gallon tank. Then again, they might have a float type brine valve in the tank that they are using to control the amount of water the unit pulls. Stranger things have been done.

If you have Post Refill, yes there should be water in the air check. If you have PRE refill, then not. Post means put the water in the salt tank at the end of the regeneration, Pre is done at the start of a regeneration.

There is always a ball in an Autotrol air check unless they are using one in the brine pickup tube at the bottom of it; required for a safety brine valve in a brine well in the brine tank.

The volume of water in the salt tank depends on the salt dose the control is set to use pre regeneration. IOWs it varies from one softener to another.

Okay Speedbump, thanks for the input. Was able to contact dealer wthout having them come out (and me waiting around for them); they say the newer units have the check valve built into the brine tank, but they still use the older 255 valve, just without the check ball. This also results in the sight glass in the check valve remaining full of water.
The Autotrol 255 valve follows a different sequence of actions than the old GE I had, and one result is that they leave a considerable amount of water in the brine tank so that the salt is maximally dissolved when the brine cycle is started.
Nice to have a dealer who has email contact and follows up on it. Will wonders never cease!
Issue closed.